Iron deficiency anemia is the most prevalent nutritional problem in the world today. Diet composition is critical since low iron intake and/or bioavailability (IB) are the main causes of the deficiency. Previously, Kapanidis and Lee (I) showed that cooked cruciferous vegetables increased extrinsic IB three to four fold and could improve iron nutrition. The objective of the present study is to evaluate the effect of cooking on in vitro IB of various vegetables for their potential for improving iron nutrition and combating anemia. Forty-eight kinds of vegetables were studied for their IB (expressed as Iron dialyzability, ID) in both raw and cooked forms. A wide variation in ID was observed, ranging from 0.2% to 33.8%. Cooking resulted in higher ID in 37 of the 48 samples. Other heating processes, such as oven drying and stir-frying, were also examined and showed increased ID. We can assign these vegetables into three categories based on their ID and enhancement by cooking. Possible mechanisms for ID increases are discussed.